分类目录归档：Oracle性能优化

oracle性能优化

分析一例 TX Enqueue contention案例

发表于 2012 年 7 月 5 日由惜分飞

应用反馈某个业务比较慢,需要紧急处理
查询等待事件

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.8.0 - 64bit Production
PL/SQL Release 9.2.0.8.0 - Production
CORE    9.2.0.8.0       Production
TNS for IBM/AIX RISC System/6000: Version 9.2.0.8.0 - Production
NLSRTL Version 9.2.0.8.0 - Production

SQL> select A.INST_ID,count(*), event
  2    from Gv$session_wait a
  3  where event not in ('SQL*Net more data to client',
  4  'rdbms ipc message',
  5               'smon timer',
  6               'pmon timer',
  7               'SQL*Net message from client',
  8               'lock manager wait for remote message',
  9               'ges remote message',
 10               'gcs remote message',
 11               'gcs for action',
 12               'client message',
 13               'pipe get',
 14               'null event',
 15               'PX Idle Wait',
 16               'single-task message',
 17               'PX Deq: Execution Msg',
 18               'KXFQ: kxfqdeq - normal deqeue',
 19               'listen endpoint status',
 20               'slave wait',
 21               'wakeup time manager','jobq slave wait')
 22  group by INST_ID,event
 23  order by 1 desc,2 desc;

   INST_ID   COUNT(*) EVENT
---------- ---------- --------------------------------------
         2          8 enqueue
         2          1 async disk IO
         2          1 db file sequential read
         2          1 SQL*Net message to client
         2          1 PX Deq: reap credit
         1          2 global cache cr request
         1          1 async disk IO
         1          1 PX Deq: reap credit
         1          1 PX Deq: Execute Reply

9 rows selected.

发现enqueue等待有些多,怀疑是TX enquenue,查询阻塞者

SQL> set linesize 100
SQL> set pagesize 66
SQL> col c1 for a15
SQL> col c1 heading "Program Name "
SQL> select l.inst_id,l.SID,program c1,l.TYPE,l.ID1,l.ID2,l.LMODE,l.REQUEST
  2  from gv$lock l,gv$session s
  3  where l.type like 'TX' and l.REQUEST =6
  4  and l.inst_id=s.inst_id and l.sid=s.sid
  5  order by id1
  6  / 

   INST_ID        SID Program Name    TY        ID1        ID2      LMODE    REQUEST
---------- ---------- --------------- -- ---------- ---------- ---------- ----------
         2        295 rtStopMain@zwq_ TX    1441805    2391806          0          6
                      bill_2 (TNS V1-
                      V3)

         2        992 rtStopMain@zwq_ TX    1441805    2391806          0          6
                      bill_2 (TNS V1-
                      V3)

         2       1238 rtStopMain@zwq_ TX    6946827    2546365          0          6
                      bill_2 (TNS V1-
                      V3)

         2       1298 rtStopMain@zwq_ TX    6946827    2546365          0          6
                      bill_2 (TNS V1-
                      V3)

         2       1684 rtStopMain@zwq_ TX    6946827    2546365          0          6
                      bill_2 (TNS V1-
                      V3)

         2       1553 rtStopMain@zwq_ TX    6946827    2546365          0          6
                      bill_2 (TNS V1-
                      V3)

         2         75 rtStopMain@zwq_ TX   12451856     199146          0          6
                      bill_2 (TNS V1-
                      V3)

         2       1125 rtStopMain@zwq_ TX   14352404      63837          0          6
                      bill_2 (TNS V1-
                      V3)

查询持有者

SQL> set linesize 100
SQL> set pagesize 66
SQL> col c1 for a15
SQL> col c1 heading "Program Name "
SQL> select l.inst_id,l.SID,program c1,l.TYPE,l.ID1,l.ID2,l.LMODE,l.REQUEST
  2  from gv$lock l,gv$session s
  3  where l.type like 'TX' and l.LMODE =6 and (l.ID1,l.ID2) in
  4  (select id1,id2 from gv$lock where type like 'TX' and REQUEST =6)
  5  and l.inst_id=s.inst_id and l.sid=s.sid
  6  order by id1
  7  / 

   INST_ID        SID Program Name    TY        ID1        ID2      LMODE    REQUEST
---------- ---------- --------------- -- ---------- ---------- ---------- ----------
         2         75 rtStopMain@zwq_ TX    1441805    2391806          6          0
                      bill_2 (TNS V1-
                      V3)

         2        992 rtStopMain@zwq_ TX    6946827    2546365          6          0
                      bill_2 (TNS V1-
                      V3)

         2        295 rtStopMain@zwq_ TX   12451856     199146          6          0
                      bill_2 (TNS V1-
                      V3)

         2       1553 rtStopMain@zwq_ TX   14352404      63837          6          0
                      bill_2 (TNS V1-
                      V3)

通过持有者和阻塞者可以得出:
1.持有者和阻塞者都是在2号实例上
2.持有者75阻塞了295/992的会话
3.持有者992阻塞了1238/1298/1684/1553的会话
4.持有者295阻塞了75的会话
5.持有者1553阻塞了1125的会话
6.同时分析发现,所有的持有者sid也在阻塞者中,也就是持有者阻塞了某个sid,而自身又被其他sid给阻塞,形成了多级阻塞或者环.如:75阻塞了295,而295有阻塞了75;992阻塞了1553,而1553阻塞了1125

查询阻塞和持有者对象

SQL> set linesize 110
SQL> col c0 for 999
SQL> col c0 heading "INS"
SQL> col c1 for a15
SQL> col c1 heading "Program Name "
SQL> select inst_id c0,sid,program c1,ROW_WAIT_OBJ# object_no, ROW_WAIT_FILE# Rfile_no,
  2  ROW_WAIT_BLOCK# Block_no ,ROW_WAIT_ROW# Row_no
  3  from gv$session
  4  where (inst_id,sid) in (select inst_id,sid from gv$session_wait where p1='1415053318')
  5  / 

 INS        SID Program Name     OBJECT_NO   RFILE_NO   BLOCK_NO     ROW_NO
---- ---------- --------------- ---------- ---------- ---------- ----------
   2         75 rtStopMain@zwq_    1323132         13     122601        111
                bill_2 (TNS V1-
                V3)

   2        295 rtStopMain@zwq_    1323132         13     122601        100
                bill_2 (TNS V1-
                V3)

   2        992 rtStopMain@zwq_    1323132         13     122601        101
                bill_2 (TNS V1-
                V3)

   2       1125 rtStopMain@zwq_    1323132         84      38445         70
                bill_2 (TNS V1-
                V3)

   2       1238 rtStopMain@zwq_    1323132         15     255066         41
                bill_2 (TNS V1-
                V3)

   2       1298 rtStopMain@zwq_    1323132         14     118411          8
                bill_2 (TNS V1-
                V3)

   2       1553 rtStopMain@zwq_    1323132         15     255066         19
                bill_2 (TNS V1-
                V3)

   2       1684 rtStopMain@zwq_    1323132         14     118411         21
                bill_2 (TNS V1-
                V3)

8 rows selected.

SQL> set linesize 100
SQL> set pagesize 100
SQL> col owner for a10
SQL> col object_name for a20
SQL> col object_type for a10
SQL> select owner,object_name,object_id,object_type
  2  from dba_objects
  3  where
  4  object_id in (select ROW_WAIT_OBJ# from gv$session
  5  where (inst_id, sid) in (select inst_id,sid from gv$session_wait where p1='1415053318'))
  6  / 
 

OWNER      OBJECT_NAME           OBJECT_ID OBJECT_TYP
---------- -------------------- ---------- ----------
DBACCADM   DCUSTCREDITBALANCE      1323132 TABLE

通过查询的出来,所有操作的聚焦点都是在DBACCADM.DCUSTCREDITBALANCE表上面

查询相关sql语句

SQL> SQL> set linesize 120
SQL> set pagesize 66
SQL> col c0 for 999
SQL> col c0 heading "INS"
SQL> col c1 for a9
SQL> col c1 heading "OS User"
SQL> col c2 for a9
SQL> col c2 heading "Oracle User"
SQL> col c3 for a15
SQL> col c3 heading "Program Name"
SQL> col b1 for a9
SQL> col b1 heading "Unix PID"
SQL> col b2 for 9999 justify left
SQL> col b2 heading "ORA SID"
SQL> col b3 for 999999 justify left
SQL> col b3 heading "SERIAL#"
SQL> col sql_text for a45
SQL> set space 1
SQL> break on b1 nodup on c0 nodup on c3 nodup on c1 nodup on c2 nodup on b2 nodup on b3 skip 2
SQL> select a.inst_id c0,b.sid b2,c.spid b1, b.program c3, b.username c2,b.serial# b3, a.sql_text
  2    from gv$sql a, gv$session b, gv$process c
  3   where
  4     a.address = b.sql_address
  5     and b.paddr = c.addr
  6     and a.hash_value = b.sql_hash_value
  7     and a.inst_id=b.inst_id and a.inst_id=c.inst_id
  8     and a.inst_id like '&inst_id' and b.sid like '&sid'
  9   order by c.spid,a.hash_value
 10  / 
Enter value for inst_id: 2
Enter value for sid: 75
old   8:    and a.inst_id like '&inst_id' and b.sid like '&sid'
new   8:    and a.inst_id like '2' and b.sid like '75'

 INS ORA SID Unix PID  Program Name    Oracle Us SERIAL# SQL_TEXT
---- ------- --------- --------------- --------- ------- ---------------------------------------------
   2      75 1167392   rtStopMain@zwq_ DBCUSTOPR   42815 update dcustcreditbalance  set limit_owe=:b0,
                       bill_2 (TNS V1-                   unbill_fee=:b1,prepay_fee=:b2,owe_fee=:b3,op_
                       V3)                               time=sysdate where id_no=:b4




SQL> /
Enter value for inst_id: 2
Enter value for sid: 992
old   8:    and a.inst_id like '&inst_id' and b.sid like '&sid'
new   8:    and a.inst_id like '2' and b.sid like '992'

 INS ORA SID Unix PID  Program Name    Oracle Us SERIAL# SQL_TEXT
---- ------- --------- --------------- --------- ------- ---------------------------------------------
   2     992 2760870   rtStopMain@zwq_ DBCUSTOPR   56282 update dcustcreditbalance  set limit_owe=:b0,
                       bill_2 (TNS V1-                   unbill_fee=:b1,prepay_fee=:b2,owe_fee=:b3,op_
                       V3)                               time=sysdate where id_no=:b4




SQL> /
Enter value for inst_id: 2
Enter value for sid: 295
old   8:    and a.inst_id like '&inst_id' and b.sid like '&sid'
new   8:    and a.inst_id like '2' and b.sid like '295'

 INS ORA SID Unix PID  Program Name    Oracle Us SERIAL# SQL_TEXT
---- ------- --------- --------------- --------- ------- ---------------------------------------------
   2     295 1639008   rtStopMain@zwq_ DBCUSTOPR   35740 update dcustcreditbalance  set limit_owe=:b0,
                       bill_2 (TNS V1-                   unbill_fee=:b1,prepay_fee=:b2,owe_fee=:b3,op_
                       V3)                               time=sysdate where id_no=:b4

其他阻塞者和持有者执行sql语句均和该语句相同,省略其他查询.通过这些查询可以确定是因为对dcustcreditbalance表的更新操作导致了这样的现象发生.

处理方案
1.临时处理方案:kill掉持有者
2.永久处理方案:修改这部分程序业务逻辑

发表在 Oracle性能优化 | 标签为 TX Enqueue contention | 评论关闭

To find the TX Enqueue contention in a RAC or OPS environment

发表于 2012 年 6 月 27 日由惜分飞

今天查找TX Enqueue看到的一篇文章,拿出来共享下

PURPOSE 
------------- 
To find the TX Enqueue contention in a RAC or OPS environment 

What is TX Enqueue ? 
In one word oracle is maintaining queue for transaction. 

How Many Resources ? 
1/ active transaction 

How Many Locks? 
1/transaction + 1/process waiting for a locked row by that 
transaction. 

How Many Users? 
1 + 1/ process waiting for something locked by this transaction. 

Who Uses? 
All processes 

What need to investigate? 
The mode of TX (6/4), Holding/Waiting/Requesting 

SCOPE & APPLICATION 
===================== 

This document will help to analyze the application design related to transaction bottlenecks 
and database performance tuning. 

Let start with an example: 
=================== 
create table akdas (A1 number, Col1 Varchar2(10), Col2 Varchar2(10)); 
insert into akdas values(5,'Hello','Hi'); 
insert into akdas values(6,'Sudip','Datta'); 
insert into akdas values(7,'Preetam','Roy'); 
insert into akdas values(8,'Michael','Polaski'); 

From Node 1: 
========== 
update akdas set a1=11 where a1=6; 

From Node 2: 
========== 
update akdas set a1=12 where a1=7; 
update akdas set a1=11 where a1=6;  /* this will wait for Node1: to complete the transaction */ 

This Note Is Made To Analyzing Only the TX-Mode-6 (Exclusive). 


1. Now run the following query to track down the problem: Who is waiting 
=================================================================== 
prompt 
prompt Query 1. Waiting for TX Enqueue where mode is Exclusive 
prompt ===================================== 
prompt 
set linesize 100 
set pagesize 66 
col c1 for a15 
col c1 heading "Program Name " 
select l.inst_id,l.SID,program c1,l.TYPE,l.ID1,l.ID2,l.LMODE,l.REQUEST 
from gv$lock l,gv$session s 
where l.type like 'TX' and l.REQUEST =6 
and l.inst_id=s.inst_id and l.sid=s.sid 
order by id1 
/ 

Output will be here 
=============== 
   INST_ID      SID     Program Name       TY     ID1     ID2       LMODE      REQUEST 
-----------  ---------- ------------------ ---   -------- --------  ---------- --------
         2           13  sqlplus@opcbsol   TX     393236  780       0          6 
                         2 (TNS V1-V3) 

It is clear that SID 12 of instance 2 is doing a DML and waiting on REQUEST Mode 6. 


2. Let's run the next query to find who is holding 
=========================================== 

prompt 
prompt 
prompt Query 2. Holding for TX Enqueue where mode greater than 6 
prompt ======================================= 
prompt 
set linesize 100 
set pagesize 66 
col c1 for a15 
col c1 heading "Program Name " 
select l.inst_id,l.SID,program c1,l.TYPE,l.ID1,l.ID2,l.LMODE,l.REQUEST 
from gv$lock l,gv$session s 
where l.type like 'TX' and l.LMODE =6 and (l.ID1,l.ID2) in 
(select id1,id2 from gv$lock where type like 'TX' and REQUEST =6) 
and l.inst_id=s.inst_id and l.sid=s.sid 
order by id1 
/ 

Output will be here 
=============== 
   INST_ID      SID     Program Name      TY        ID1        ID2      LMODE    REQUEST 
   ----------  ---------- -------------- ---   ---------- --------   ----------- --------
         1          12    sqlplus@opcbsol TX     393236        780      6          0 
                          1 (TNS V1-V3) 

So holder is SID 12 on instance 1. Where LMODE = 6. 


3. Let's find out the exact file#, block# and Record# where it is waiting 
=============================================================== 

prompt 
prompt 
prompt Query 3. Object# ,File#, Block# and Slot# TX Enqueue in detail 
prompt ======================================== 
prompt 
set linesize 110 
col c0 for 999 
col c0 heading "INS" 
col c1 for a15 
col c1 heading "Program Name " 
select inst_id c0,sid,program c1,ROW_WAIT_OBJ# object_no, ROW_WAIT_FILE# Rfile_no,
ROW_WAIT_BLOCK# Block_no ,ROW_WAIT_ROW# Row_no 
from gv$session 
where (inst_id,sid) in (select inst_id,sid from gv$session_wait where p1='1415053318') 
/ 

Output Will be here 
=============== 
 INS     SID    Program Name     OBJECT_NO RFILE_NO BLOCK_NO  ROW_NO 
----- ---------- -------------   ---------------    --------- -------
   2         13     sqlplus@opcbsol  7261      9        12346     1 
                      2 (TNS V1-V3) 
  

From the output, it is clear that it is waiting on Relative_File# 9, Block# 12346, Row Number 1. 
Here Row Number 1 means the slot number in the block 12346. This Row_No start from 0 (zero). 


4. Let's Find the object details 
============================= 

prompt 
prompt 
prompt Query 4. Object Involve for TX Enqueue in detail 
prompt =============================== 
prompt 
set linesize 100 
set pagesize 100 
col owner for a10 
col object_name for a20 
col object_type for a10 
select owner,object_name,object_id,object_type 
from dba_objects 
where 
object_id in (select ROW_WAIT_OBJ# from gv$session 
where (inst_id, sid) in (select inst_id,sid from gv$session_wait where p1='1415053318')) 
/ 

Output Will be here 
=============== 
OWNER      OBJECT_NAME  OBJECT_ID   OBJECT_TYP 
---------  ------------ --------    -----------
AKDAS      AKDAS        7261        TABLE 


5. Let’s find the row value details 
============================= 

prompt 
prompt 
prompt Query 5. Finding the row value 
prompt ==================== 
prompt 
select * from <Owner>.<Table Name>  where rowid like 
DBMS_ROWID.ROWID_CREATE(1,&Object_No,&Rfile_No, &Block_No, &Row_Number) 
/ 
From query 3 and 4  we will get the value for all variables. 
Owner = AKDAS 
Table_Name = AKDAS 
Object_No = 7261 
Rfile_No =  9 
Block_No = 12346 
Row_Number = 1 

Output Will be here 
=============== 
        A1    Col1                 Col2 
  ---------- --------------- ---------- 
         6      Hello                Hi 

So we can drag down to the row value where TX Enqueue contention exists. 


6. Let’s find the user activity that is "Holder" and "Waiter" 
==================================================== 

set linesize 120 
set pagesize 66 
col c0 for 999 
col c0 heading "INS" 
col c1 for a9 
col c1 heading "OS User" 
col c2 for a9 
col c2 heading "Oracle User" 
col c3 for a15 
col c3 heading "Program Name" 
col b1 for a9 
col b1 heading "Unix PID" 
col b2 for 9999 justify left 
col b2 heading "ORA SID" 
col b3 for 999999 justify left 
col b3 heading "SERIAL#" 
col sql_text for a45 
set space 1 
break on b1 nodup on c0 nodup on c3 nodup on c1 nodup on c2 nodup on b2 nodup on b3 skip 2 
select a.inst_id c0,b.sid b2,c.spid b1, b.program c3, b.username c2,b.serial# b3, a.sql_text 
  from gv$sql a, gv$session b, gv$process c 
 where 
   a.address = b.sql_address 
   and b.paddr = c.addr 
   and a.hash_value = b.sql_hash_value 
   and a.inst_id=b.inst_id and a.inst_id=c.inst_id 
   and a.inst_id like '&inst_id' and b.sid like '&sid' 
 order by c.spid,a.hash_value 
/ 

This query asks the Instance Number and Sid number, which you can get from step 1 and 2. 
But remember , you can see the waiter activity, but you may not see the holder activity. 
Reason is, the holder is sitting idle after doing the DML operation. So SQL for Holder 
should not be seen under gv$sql. 

This all query can be run for single instance database, but all GV$ view need to replace to V$ 
and there is no INST_ID for V$ View, that part need to be taken care.

来自:How to Find TX Enqueue Contention in RAC or OPS [ID 179582.1]

发表在 Oracle性能优化 | 评论关闭

resmgr:cpu quantum等待

发表于 2012 年 6 月 14 日由惜分飞

昨天晚上数据库升级(使用exp/imp从9i升级到11g),开启业务,数据库出现很多resmgr:cpu quantum等待

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
PL/SQL Release 11.2.0.2.0 - Production
CORE    11.2.0.2.0      Production
TNS for IBM/AIX RISC System/6000: Version 11.2.0.2.0 - Production
NLSRTL Version 11.2.0.2.0 - Production

SQL> SELECT sid,event FROM v$session WHERE wait_class#<>6;

       SID EVENT
---------- ----------------------------------------------------------------
        27 resmgr:cpu quantum
        38 resmgr:cpu quantum
        43 resmgr:cpu quantum
        46 resmgr:cpu quantum
       113 resmgr:cpu quantum
       118 resmgr:cpu quantum
       125 resmgr:cpu quantum
       140 resmgr:cpu quantum
       143 resmgr:cpu quantum
       199 resmgr:cpu quantum
       205 resmgr:cpu quantum

       SID EVENT
---------- ----------------------------------------------------------------
       212 resmgr:cpu quantum
       220 resmgr:cpu quantum
       221 resmgr:cpu quantum
       223 resmgr:cpu quantum
       238 resmgr:cpu quantum
       241 resmgr:cpu quantum
       301 resmgr:cpu quantum
       313 resmgr:cpu quantum
       314 resmgr:cpu quantum
       405 resmgr:cpu quantum
       410 resmgr:cpu quantum

       SID EVENT
---------- ----------------------------------------------------------------
       415 resmgr:cpu quantum
       435 resmgr:cpu quantum
       502 resmgr:cpu quantum
       503 resmgr:cpu quantum
       509 resmgr:cpu quantum
       510 resmgr:cpu quantum
       512 resmgr:cpu quantum
       521 resmgr:cpu quantum
       526 resmgr:cpu quantum
       528 resmgr:cpu quantum
       532 resmgr:cpu quantum

       SID EVENT
---------- ----------------------------------------------------------------
       533 enq: TX - row lock contention
       589 resmgr:cpu quantum
       596 resmgr:cpu quantum
       600 resmgr:cpu quantum
       609 resmgr:cpu quantum
       611 resmgr:cpu quantum
       625 resmgr:cpu quantum
       635 null event
       707 resmgr:cpu quantum
       727 resmgr:cpu quantum
       731 SQL*Net message to client

44 rows selected.

查询alert日志

Sat Jun 09 06:00:00 2012
Setting Resource Manager plan SCHEDULER[0x310C]:DEFAULT_MAINTENANCE_PLAN via scheduler window
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Sun Jun 10 02:00:00 2012
Closing Resource Manager plan via scheduler window
Clearing Resource Manager plan via parameter

Sun Jun 10 06:00:00 2012
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Mon Jun 11 02:00:00 2012
Closing Resource Manager plan via scheduler window
Clearing Resource Manager plan via parameter

Mon Jun 11 22:00:00 2012
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Tue Jun 12 02:00:00 2012
Closing scheduler window
Closing Resource Manager plan via scheduler window
Clearing Resource Manager plan via parameter

Tue Jun 12 22:00:00 2012
Setting Resource Manager plan SCHEDULER[0x3108]:DEFAULT_MAINTENANCE_PLAN via scheduler window
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Wed Jun 13 02:00:00 2012
Closing scheduler window
Closing Resource Manager plan via scheduler window
Clearing Resource Manager plan via parameter

从这里可以看出来，因为SCHEDULER定时启动和关闭资源管理的DEFAULT_MAINTENANCE_PLAN从而导致在晚上10点到2点Resource Manager plan处于启用状态.上线测试刚好在晚上2点之前,所有当时查询的时候发现很多resmgr:cpu quantum等待是因为Resource Manager plan启用导致(使用SCHEDULER控制其启用和关闭),很多情况下数据库跑的应用比较单一，不是十分的需要启动资源管理.
在11g中关闭方法如下

1. Set the current resource manager plan to null (or another plan that is not restrictive):

alter system set resource_manager_plan='' scope=both;

2. Change the active windows to use the null resource manager plan (or other nonrestrictive plan) using:

execute dbms_scheduler.set_attribute('WEEKNIGHT_WINDOW','RESOURCE_PLAN',''); 
execute dbms_scheduler.set_attribute('WEEKEND_WINDOW','RESOURCE_PLAN','');

3. Then, for each window_name (WINDOW_NAME from DBA_SCHEDULER_WINDOWS), run:

execute dbms_scheduler.set_attribute('<window name>','RESOURCE_PLAN','');

SQL> select WINDOW_NAME  from DBA_SCHEDULER_WINDOWS;

WINDOW_NAME
------------------------------
MONDAY_WINDOW
TUESDAY_WINDOW
WEDNESDAY_WINDOW
THURSDAY_WINDOW
FRIDAY_WINDOW
SATURDAY_WINDOW
SUNDAY_WINDOW
WEEKNIGHT_WINDOW
WEEKEND_WINDOW

9 rows selected.

发表在 Oracle性能优化 | 标签为 resmgr:cpu quantum | 4 条评论

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分类目录归档：Oracle性能优化

分析一例 TX Enqueue contention案例

To find the TX Enqueue contention in a RAC or OPS environment

resmgr:cpu quantum等待

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分类目录归档：Oracle性能优化

分析一例 TX Enqueue contention案例

To find the TX Enqueue contention in a RAC or OPS environment

resmgr:cpu quantum等待

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